why bother changing your spark plug wireset on 1mz-fe even if car runs "fine"?

[fenixus]

I have postponed swapping the spark plug wireset on my 1mz-fe for long enough. even at 130k miles I had no misfire problem, nor any kind of CEL or actually nothing I could notice ...so why bother changing your spark plug wireset on 1mz-fe even if car runs "fine"?

answer no.1
because it's an item of minor tune up procedure

answer no.2
because you never know how bad and restrictive (talking about electrical resistance here) old wires were until you measure them (and perhaps swap them out at same time)

answer no.3
because PROBABLY the A/F mixture for the rear bank (fired from wires) is RICHER than the front bank

here is a few reference pics from my '02 solara with normal (non-VVT-i 1mz-fe), having 3 coil packs in front and wires running to the rear bank.

Perhaps those pics will help others while swapping just the wires and keeping the old plastic bracket in there, certainly it helped me, because all the damn plastic clips and specific wire routing is a tad crazy if you ask me...

Pics from car how the "loose" clips are holding wires and how things are routed to front bank:
Wires are numbered from left to right 5, 1 and 3 and they sit on corresponding ignition coils over cylinders (again from left to right) 2, 4 and 6.



Pics after removing the WHOLE wireset (together with bracket of course) with close ups on tight clips at bottom



Bracket clips removed (tools in pic), broke partially only 1 super tight clip on the outer edge of bracket (pretty much 1 time use only) and 1 single tiny single wire clip (irrelevant):


Progress:


Swap done:


and here is the end result as everything is installed back on engine



NOW, the difference per my OBD2 scanner and multimeter:

a) before (130k old Yazaki wireset)
front bank's (no.2 per specs) Long Term Fuel Trim around 0%
rear bank's (no.1 per specs) Long Term Fuel Trim around -5%

resistance readings on old wires:
Cyl #1 to coil pack over cyl #4 wire reads 14.2Kohm
Cyl #3 to coil pack over cyl #6 wire reads 18.2Kohm
Cyl #5 to coil pack over cyl #2 wire reads 16.3Kohm

... but it's nothing out of specs, right?

b) after (brand new NGK TE65 wireset)
front bank's (no.2 per specs) Long Term Fuel Trim around 0%
rear bank's (no.1 per specs) Long Term Fuel Trim around 0%

resistance readings on new wires:
Cyl #1 to coil pack over cyl #4 wire reads 7.1Kohm
Cyl #3 to coil pack over cyl #6 wire reads 9.1Kohm
Cyl #5 to coil pack over cyl #2 wire reads 8.2Kohm

For sure the car has restored its power in the high band, I actually have driven this car on highways a bit like I stole it and it seems much stronger in high RPMs (up to WOT). difference is not really visible at idle or in mid-range (maybe a bit).

Still wondering if my city driving MPG improves now
HTH

EDIT:
this is the cheap (not easy) route with awesome NGK wires at $31 from Advance Auto Parts
there is another (easy) route with an OEM wireset which actually at around $60 comes pre-installed on the bracket, so it's a simple plug'n'play swap with no broken clips trouble

[BMR]

Nice job on the write up fenixus! I did this on my Avy a few months ago. Used the same wireset as you did. Even tho I took a few pics of the wire routing thru that plastic duct, I was still scratching my head as I was trying to reassemble it. Took me a while to figure out I had the blasted thing backwards! Mine had ~130k on the plugs/wires, and even though I hadn't really noticed any problems with misfiring or anything, it did seem to run better. More responsive, mostly.

Edit: Just noticed there's no sticky thread covering this. There's one for the 6-coil 1MZ, but not this 3 coil waste spark setup. So I'm gonna add this one.

[fenixus]

thanks BMR!

yes, better responsiveness. actually Iwas thinking it was my transmission at slight fault before swapping wires, still not entirely liking Mobil1 ATF though.

to be honest, even with pics it took me a while to put it back together. most of time I spent on carefully opening the clips and still I broke a piece of the one on front bank end (seems 1 time use to me, it's locked on every possible side) and then I broken off the single wire clip when prying it open (it lays among others in one of pics).

the next trouble was placement of new wires in the bracket clips so I don't end up with too short wires on rear bank side (or vice versa) ... had to take a careful look at old "dinged" and dented wires to match them up correctly like originals. it would honestly suck to end with too short wires on one of the sides

next time, I will be going with OEM wireset and a new pre-assembled bracket along with it. to hell with those clips!

in an hour or two I am taking this car for a run to further store (highways), so i will have a chance to feel it at hwy cruising speeds (going with wifey)

I am glad I did that swap though, multimeter and OBD2 scanner results are strong evidence

EDIT:
and thanks for making it a sticky!

Originally Posted by BMR

Nice job on the write up fenixus! I did this on my Avy a few months ago. Used the same wireset as you did. Even tho I took a few pics of the wire routing thru that plastic duct, I was still scratching my head as I was trying to reassemble it. Took me a while to figure out I had the blasted thing backwards! Mine had ~130k on the plugs/wires, and even though I hadn't really noticed any problems with misfiring or anything, it did seem to run better. More responsive, mostly.

Edit: Just noticed there's no sticky thread covering this. There's one for the 6-coil 1MZ, but not this 3 coil waste spark setup. So I'm gonna add this one.

[fenixus]

just returned from a store and was driving alone

... man ... there is MUCH more restored power to the car all over the band, much more than I thought initially
it feels very responsive now, even when gently pressing gas pedal while cruising (depends on transmission gear and time it gets out of O/D and such but still) ... and generally this car flies like a rocket again now

[JohnGD]

Nice writeup, especially with the OBDII readout comparing the old and new wire sets. I guess it DOES help to replace some old parts even if they're within spec!! I wonder if the same can be said of spark plugs.

Maybe it's the old wires, or maybe it's NGK! FTW.

So what's with the Mobil-1 ATF?

[fenixus]

thank you

I believe the same applies to spark plugs. old ones will work and don't cause misfire or anything like a CEL ... but I bet the spark is not as strong as with a younger part

I always wondered why Haynes recommends short minor tune up intervals on those cars... well I think I know why now it restores the power which step by step goes missing as ignition components age and wear down (still in specs of course).

I doubt it's the magic of NGK, however I like those stiff and thick blue wires very much using them on both cars now

ehhh, I have a feeling like Mobil1 ATF is not as good as Castrol IMV ATF or ... rather Mobil1 ATF went towards thin Dex-VI specs and some performance improvements instead of holding on to older specs? after all they meet A LOT of new luxury car specs while Castrol ATF doesn't I think ... perhaps it's just Castrol IMV being a tad thicker which is actually better in an old and worn transmission? not sure.

my transmission is not shifting as smooth as it used to, after I switched it Mobil1 ATF... or maybe it's the Magnefine filter lowering the line pressure a bit? really not sure .. but I use Magnefine on other car too and have zero trouble with smoothness of gear shifting (using Castrol IMV over there)... I think, based on other member opinion (blown diff seals after a year from switch to Mobil1) that Mobil1 ATF fluid is different from Castrol (which sounds safer in that matter).

other thing, it could my worn out engine and transmission mounts on V6 making me feel those jerks ... (kick down cable has been adjusted back to its OEM position for now, no need for "sporty" adjustment after TPS and wireset were swapped).

other thing (again it could be coincidence), my V6's power steering feels kinda stiffer and heavier than very light PS on 5s-fe (again all same except of fluid, using Castrol over there) ... really not convinced Mobil1 ATF is of any good in those older cars...

Originally Posted by JohnGD

Nice writeup, especially with the OBDII readout comparing the old and new wire sets. I guess it DOES help to replace some old parts even if they're within spec!! I wonder if the same can be said of spark plugs.

Maybe it's the old wires, or maybe it's NGK! FTW.

So what's with the Mobil-1 ATF?

[JohnGD]

The latest version of Mobil-1 went back to the plain Dexron-III specs, no longer the T-IV types of applications, just plain D-III. So it should be as close to that as it can be.

Mobil does have a syn-blend Dexron-VI, but with Valvoline fully synthetic and Walmart SuperTech so easy to find no sense using it for GM's excellent Hydramatic transmissions. Now Ford co-developed the 6F series with GM, but one member pointed it out different from GM, the 6F35 is a POS in the Fusion, probably worse than the U-series.

Yeah I do agree a thicker ATF is better in these transmissions, that's why I never recommended Dexron-VI like fluids in D-III applications. I'd think Mobil-1 is still the thicker version, but hmmm, maybe throw it out and use the Castrol instead.

But this is easy to find out.

I don't use Mobil-1 gear oils or their red grease. The specs aren't as good as the Valvolines. Dunno, maybe their engine oil is the only good stuff now. That would be too bad.

[Brandoe91]

Good job on the write-up/ review. I like that you did the before and after resistance check and OBDII data.

[fenixus]

Originally Posted by JohnGD

Yeah I do agree a thicker ATF is better in these transmissions, that's why I never recommended Dexron-VI like fluids in D-III applications. I'd think Mobil-1 is still the thicker version, but hmmm, maybe throw it out and use the Castrol instead.

But this is easy to find out.

I don't use Mobil-1 gear oils or their red grease. The specs aren't as good as the Valvolines. Dunno, maybe their engine oil is the only good stuff now. That would be too bad.

that's what I am afraid of. I will be switching this car to ol' god Castrol IMV in Spring (now we have kinda Winter sometimes here LOL!) and see it that helps.

I also seem to trust only Mobil1 motor oils, their other products are weird. I have no idea which line of Mobil1 ATF I got (dex-VI or dex-III specs), but I thin it mentioned Type T-IV on the label, so it was closer to Dex-VI stuff, right?

[JohnGD]

The T-IV is actually still the thicker stuff, some say just highly friction modified Dexonr III for U-series' partial lock-up converters. The WS is the thin stuff. I don't know why the transmission isn't shifting as smoothly.

But that's also why I'm wary of the Valvoline MaxLife that's Dexron VI thin.

[fenixus]

yeah, I don't get it either, maybe nothing wrong with Mobil1 and it's just my guts feeling it all wrong...

I avoid Valvoline Maxlife like fire given the things I read about their formulas (made to meet the LATEST specs, not so much the older ones) ... I will give Castrol a shot and see what happens, perhaps the problem is elsewhere. not too big of a deal, but still, makes me wonder why.

Originally Posted by JohnGD

The T-IV is actually still the thicker stuff, some say just highly friction modified Dexonr III for U-series' partial lock-up converters. The WS is the thin stuff. I don't know why the transmission isn't shifting as smoothly.

But that's also why I'm wary of the Valvoline MaxLife that's Dexron VI thin.

[slpr1mz]

$31 that's pretty cheap now if i can get my car to start i'd b looking into the change. what your preference on spark plugs? cause i tried the NGK's but moved back to the denso's after a short time.

nice thread!

[xpeed]

Damn, you've sold me on this. I might have to pick this up as well.

[fenixus]

Originally Posted by slpr1mz

$31 that's pretty cheap now if i can get my car to start i'd b looking into the change. what your preference on spark plugs? cause i tried the NGK's but moved back to the denso's after a short time.

nice thread!

Thanks
$31 was after online discount code (A123 - $20 off $50) and local pickup, good deal and you have it almost right away.

Which NGK plugs did you try?
I use NGK Laser Platinums in 5s-fe and they are very good even after a few years, no problems.
NGK Laser Platinum plugs are equal to Denso Double Platinum plugs (I use those on V6).

NGK/NTK are same good (if not better) OEM parts as Denso is for plugs, oxygen sensors, wiresets, etc.

Originally Posted by xpeed

Damn, you've sold me on this. I might have to pick this up as well.

good luck

I had to do this in a rush yesterday after I had to take an unpredicted day off from work. I was lucky the weather was Spring alike (60F), so I did what has to be done. anyways, glad I did this, because since this morning "Winter is Coming" again

[slpr1mz]

i used the single pronged iridiums. i goofed hahha. i quickly fixed the issue and went back to denso's...